Effect of preliminary surface working on fatigue strength of type 304 stainless steel at ambient temperature and 288 deg C in air and pure water environment

Effect of preliminary surface working on the fatigue strength of type 304 stainless steel in air and pure water at ambient temperature and 288 deg C was examined. The surface finishings were electro-polishing, emery paper polishing, shot peening, shot peening followed by emery paper polishing, and glassbead peening. While the residual stress introduced by shot peening was very highly compressive, the fatigue strength was not so much increased. However, the fatigue strength of the shot peened and then emery paper polished stainless steel was remarkably increased. The fatigue strength of the glassbead shot peened stainless steel in air was much improved compared with the shot peened stainless steel. The fatigue strength of the glassbead peened stainless steel was also increased in high temperature water, but the degree of improvement was not so high compared with that in air.